org.jscsi.target.scsi.cdb

Class CommandDescriptorBlock

java.lang.Object

org.jscsi.target.scsi.cdb.CommandDescriptorBlock

Direct Known Subclasses:

FormatUnitCDB, InquiryCDB, ModeSense6Cdb, ReadCapacityCdb, ReadOrWriteCdb, ReportLunsCDB, RequestSenseCdb, SendDiagnosticCdb, TestUnitReadyCdb

public abstract class CommandDescriptorBlock
extends Object

An abstract class for accessing the variables common to Command Descriptor Blocks of all sizes.

A Command Descriptor Blocks is a blocks of multiple bytes that contains a ScsiOperationCode, specifying a command the SCSI initiator wants the SCSI target to perform and related fields, which determine details of the ordered task.

Since all fields in the Control byte except for the Normal ACA bit are either reserved, obsolete, or vendor specific, the NACA bit can be accessed directly from this class.

Author:

Andreas Ergenzinger

Constructor Summary

Constructors

Constructor and Description
CommandDescriptorBlock(ByteBuffer buffer) The abstract constructor.

Method Summary

Methods

Modifier and Type	Method and Description
protected void	addIllegalFieldPointer(int byteNumber) Adds an instance FieldPointerSenseKeySpecificData, which specifies an illegal field by the position of its first byte, to illegalFieldPointers.
protected void	addIllegalFieldPointer(int byteNumber, int bitNumber) Adds an instance FieldPointerSenseKeySpecificData, which specifies an illegal field by the position of its first byte and its first bit, to illegalFieldPointers.
FieldPointerSenseKeySpecificData[]	getIllegalFieldPointers() Returns null if there were no illegal fields in the serialized CDB passed to the constructor, or an array of appropriate FieldPointerSenseKeySpecificData, that have to be enclosed in the SenseData returned to the initiator (with sense key SenseKey.ILLEGAL_REQUEST and additional sense code and sense code qualifier AdditionalSenseCodeAndQualifier.INVALID_FIELD_IN_CDB).
ScsiOperationCode	getScsiOperationCode()
boolean	isNormalACA() The NACA (Normal ACA) bit specifies whether an auto contingent allegiance (ACA) is established if the command terminates with CHECK CONDITION status.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CommandDescriptorBlock

public CommandDescriptorBlock(ByteBuffer buffer)

The abstract constructor.

Deserializes the first byte containing the SCSI Operation Code and the Control byte.

The passed ByteBuffer parameter must have a capacity ≥ the length of the specific command descriptor block. Since this is assured by the SCSICommandParser.getCDB() method, which always returns ByteBuffer objects with capacity 16, no checks will be performed.

Parameters:

buffer - contains the serialized CDB starting at index position zero

Method Detail

getScsiOperationCode

public final ScsiOperationCode getScsiOperationCode()

isNormalACA

public final boolean isNormalACA()

The NACA (Normal ACA) bit specifies whether an auto contingent allegiance (ACA) is established if the command terminates with CHECK CONDITION status. A NACA bit set to one specifies that an ACA shall be established. A NACA bit set to zero specifies that an ACA shall not be established.

Returns:

true if the Normal ACA bit in the CDB's Control byte is set and false if it is not.

addIllegalFieldPointer

protected final void addIllegalFieldPointer(int byteNumber)

Adds an instance FieldPointerSenseKeySpecificData, which specifies an illegal field by the position of its first byte, to illegalFieldPointers.

Parameters:

byteNumber - index of the first byte of the illegal field

addIllegalFieldPointer

protected final void addIllegalFieldPointer(int byteNumber,
                          int bitNumber)

Adds an instance FieldPointerSenseKeySpecificData, which specifies an illegal field by the position of its first byte and its first bit, to illegalFieldPointers.

Parameters:

byteNumber - index of the first byte of the illegal field

bitNumber - index of the first bit of the illegal field

getIllegalFieldPointers

public final FieldPointerSenseKeySpecificData[] getIllegalFieldPointers()

Returns null if there were no illegal fields in the serialized CDB passed to the constructor, or an array of appropriate FieldPointerSenseKeySpecificData, that have to be enclosed in the SenseData returned to the initiator (with sense key SenseKey.ILLEGAL_REQUEST and additional sense code and sense code qualifier AdditionalSenseCodeAndQualifier.INVALID_FIELD_IN_CDB).

Returns:

null or an array of appropriate FieldPointerSenseKeySpecificData